3 Answers

Since I just replaced a Samsung Galaxy S6 screen yesterday, it's probably the touch sensor button cable which is connected to the charger port flex assembly. Sounds like you've cut or damaged the flex cable on accident.

So home button and finger print work, but the back button does not work at all and the menu button works and lights up?

Anyway, the charger port assembly has two separate cables going to each corner for each touch sensor.

TL:DR - Yes, a daughter-board replacement will fix this issue (Charger port flex assembly). Problem is that you will need to take out the screen again.

Next time if you do open it, you will need to start lifting up the screen from top then to bottom. Then you can separate the touch sensors being glued to the glass by using a spudger between them.

Hi my initial thought was exactly what you are referring to the sensors inside LCD. My recent and back button both light up when I start the phone up from the phone being off. So when Samsung loads my buttons light up after I get into home screen lights don't work anymore. So my thought was that there is a tiny cable attached to the charger port which I did replace , I am thinking the cable is loose? The keys work but don't light up once I am in the home screen.

I changed the display, the entire display, so I did not remove the screen or anything. could be that I damaged some cables during the process? any idea on how to proceed? the daughter board would be that little extra piece at the button with the 4 screws?

I have a blue cable in there, I guess bring power to the buttons, the home button works so that cable should be ok right? what else can be damaged?